Gte Sylvania Incorporated

Gte Products Corporation

William Scheithauer, Jr

Joseph E Ritsko

Clarence D Vanderpool

Howard L Acla

Geoffrey L Harris

Glenn Albert Shaffer

James J Oakes

A uniform mixture of refractory metal carbide, binder metal and a pressing aid is achieved by fluidizing the mixture.

Intimate mixtures of refractory metal carbides and a binder metal

Extra fine cobalt metal powder (up to about 0.8 microns) having less than 100 parts per million cation impurities is produced by a process in which cobalt pentammine chloride is digested in a dilute ammonium hydroxide solution to form a black precipitate, which is separated and heated in a hydrogen atmosphere to reduce the precipitate directly to cobalt metal powder. The cobalt pentammine chloride may be obtained by digesting a cobalt source in hydrochloric acid, adding ammonium hydroxide, oxidizing the cobaltous ion to cobaltic ion, and reducing the pH with hydrochloric acid to less than 1.0 in order to precipitate cobalt pentammine chloride. The final cobalt metal powder is useful, for example, as a starting material in the manufacture of cemented carbides.

Method for producing extra fine cobalt metal powder

A process for producing a refractory carbide grade powder having improved particle size distribution and pressing characteristics. The process comprises forming an aqueous slurry of a standard refractory metal carbide powder and the desired matrix, attritor milling for 1 to 10 hours, removing the milled slurry from the mill, forming an aqueous slurry having a desired solid concentration, adding a water-soluble relatively long chain polyglycol as a pressing aid and spray drying the slurry to form spherical particles suitable for pressing and sintering. During sintering less grain growth of the refractory metal carbide grade powders occurs than with conventional grade powders sintered under essentially the same temperature conditions.

Process for producing refractory carbide grade powder

A cemented carbide composition is disclosed that consists essentially of a carbide of a refractory metal selected from Group 4, Group 5, and Group 6 metals and mixtures thereof and a binder selected from one of the foregoing refractory metals and from 0.5 to 1.5% by weight of an iron group metal. A process for producing these materials is also disclosed which comprises forming an intimate admixture of the desired refractory metal carbide, the desired refractory metal, an iron group metal, a paraffin wax and a volatile mixing aid. Thereafter, the mixing aid is removed by heat. The resulting powder particles are compacted to a predetermined shape and heated at a temperature sufficient to remove the wax and thereafter are heated at a temperature above the melting point of the catalyst and thereafter elevated in temperature to achieve suitable sintering.

Growing community of inventors

Athens, PA, United States of America

William Scheithauer, Jr